中文说明：复化三点Gauss-lengend公式求pi，仿真效果非常好，相关分析过程的matlab方法，正确率可以达到98％，基于chebyshev的水声信号分析，是信号处理的基础。
English Description：
The complex three point Gauss-lengend formula for PI, simulation results are very good, the correlation analysis process of the MATLAB method, the correct rate can reach 98%, Chebyshev based on the acoustic signal analysis, is the basis of signal processing.